A recording released by Islamic State reveals member who killed journalist
James Wright Foley speaking in British accent

A video released by Islamic State militants purporting to be of the beheading of American journalist James Wright Foley, who was kidnapped in Syria in 2012, shows his killer dressed all in black and speaking with aBritish accent.

The video appears to be evidence of the increasing sophistication of the Islamic State group's media arm.

It begins with scenes ofPresident Barack Obama explaining his decision to order airstrikes, before cutting to a man with a shaved head, believed to be Foley, in an orange jumpsuit kneeling in the desert next to the black-clad militant.

Mr Foley's name appears in both English and Arabic graphics on screen. He is wearing a clip-on microphone and is filmed reading out a statement from the group.

When Mr Foley has finished speaking, the IS militant then makes a minute-long speech in a clear British accent, threatening US President Barack Obama with more violence against the American people.

"You're no longer fighting an insurgency," he declares. "We are an Islamic army, an estate that has been accepted by a number of Muslims worldwide. So, effectifvely, any agression towards the Islamic State is an aggression towards Muslims of all walks of life who have accepted the Islamic Caliphate as their leadership.

"So, any attempt by you, Obama, to deny the Muslims their rights of living in safety under the Islamic Caliphate, will result in the bloodshed of your people."